Apex 3.0 Release Notes

Introduction

Apex 3.0 is a major revision of Apex that provides enhanced AI reasoning and autonomy services, a revamped graphical user interface (Sherpa), an improved interface for defining applications, and numerous other enhancements.

Enhancements

Sherpa

• A new web browser-like user-interaction model including: backward/forward history control, an explicit focal object represented as a URL, correspondence between data objects of interest (structures manipulated by AI reasoning services) and items that can selected as the focal object, and the ability to create multiple viewer instances (floating windows).

• Redesigned so that view types are now aligned with the types of AI services provided by Apex:

• Task Agenda. A new view illustrating the state of task execution for an agent at any given instant. Every task on the agenda is displayed in a hierarchical table that can be expanded or collapsed to show or hide subtasks, respectively. Detailed information about each task, including state, resources, and times are displayed in columns.

• Monitor View. A new view that depicts a monitor graphically. The monitor and its component conditions are displayed in a color-coded graph that clearly reveals their satisfaction status.

• PDL View. A new view that, in one column, lists all procedures for a given agent, sorted alphabetically, by bundle, or by calling hierarchy. A second column displays the code for a selected procedure.

• State Variable View. A new view that presents, as a table, the values of all state variables for a selected agent over time.

• Object Diagram. A revamped version of the previous, limited diagram facility. Diagrams now can be attached to any object. Two kinds of diagrams are supported: photo (for example, JPG image) and wireframe (two-dimensional line drawing). Diagrams can have mouse- sensitive regions that correspond and link to the actual Apex objects they represent. By default, all objects have a graph diagram, which is a box and arrow representation of the object’s subpart structure.

• Trace View. A revamped version of the previous Trace View. Events are now decomposed into their logical parts and displayed in a table with numerous additional (and customizable) columns. Hyperlinked event components are clickable for quick navigation to their related views.

• Object Tree. An enhanced version of the previous Object Tree. All objects in an Apex application are now accessible in an expandable/collapsible hierarchy rooted at the application itself. Any object can be selected to make it the new focal object and to request desired views.

• Inspection View. An enhanced version of the previous Inspection View, made clearer by removing uninteresting class slots.

• Enhanced step/pause interface. A new pull-down menu allows the setting of specific times, time intervals, or step intervals at which to automatically pause an application.

AI Reasoning Services

• New framework and language extensions for advanced monitoring and querying, including support for measurements, estimations, trends, as well as complex and time-based conditions.

• Ability to specify logging policies for measurements (the new log step level clause).

• Support for indexical variables (variables surrounded by “+” characters that denote functions called with the current task to obtain a value).

• A new syntax (surrounding angle brackets) for expressing when ordinary PDL variables are expected to be bound, thus preventing unintended bindings.

• A new procedure type called Primitives to represent the low level skills of an agent. Primitives replace Activities (and obviate the need for the requisite CLOS programming).

• Sequential and ranked procedures now support procedure and step level clauses (they also now require explicit step clauses).

• New syntax shortcuts for procedures:

• The step name (tag) can be omitted. When omitted, a name for the step is automatically generated from the first symbol in the task description, for example:

(step (reach ?object with ?hand)) 
  ... 
  (step (grasp ?object with ?hand) (waitfor  ?reach))

• The index of a procedure can be given as the first or second argument to the procedure, instead of using an index clause, for example:

(procedure :sequential (pick up ?object with ?hand) ...)

• New step-level clauses repeating and responding, for repetition and response policies (replacing the period clause), log for logging policies of measurements, and on-start and on-end for specifying Lisp code to evaluate around task executions.

• New procedure-level clauses terminate (alternative to step-level clause of the same name) and expected-duration.

• Better handling of cogevents received by an agent: order is preserved, asynchronous events are not lost, and the *transient-cogevents* flag is obsoleted.

• New schedule form for scheduling actions with PDL or from Lisp.

Application support

• Simplified interface for creating agents and resources.

• Publish-subscribe mechanism for communication between agents.

• Support for ISO-standard duration expressions.

Miscellaneous enhancements

• Improved performance in speed and memory usage.

• Numerous bug fixes and miscellaneous enhancements in both Apex and Sherpa.

• Many new example applications.

• A new tutorial on creating Apex applications.

Apex license information

Apex is built upon Allegro Common Lisp (R) produced by Franz, Inc. Franz requires users of Apex to accept its license agreement, which pertains primarily to the use of the Franz components of the Apex software. The agreement is available in a file named agreement.txt located in the Apex installation directory.

Apex documentation

The following documents contain information relevant to Apex:

• The Apex Reference Manual contains detailed instructions for using Apex and creating Apex applications.

• The tutorial Paper Covers Rock: An Apex Tutorial teaches you how to write basic Apex applications, by writing more and more complication versions of the game Rock, Scissors, Paper.

Apex documentation may be revised after the release of Apex 3.0. To obtain the latest version of the documentation, visit the Apex Documentation Wiki.

Known issues

• On the Macintosh, Sherpa works best when the “Look & Feel” setting (in the View menu) is set to Metal. There may be minor display or interaction problems if other settings are used.

• On the Macintosh, object diagram display is slow. You need to wait a bit for the diagram to finish rendering. You may also need to zoom-in and zoom-out to see the diagram properly sized. A network timeout error sometimes leaves Sherpa unresponsive. If this happens you must quit Sherpa manually (that is, from the Force Quit menu in the Finder) and restart it.

• On Windows, each time time Sherpa is started, it asks for agreement with the Apex user license. This is a software bug -- the license agreement should be presented only on the very first start of the system.

• Some features will not work when running Sherpa and Apex on different machines. Most importantly, you can only load applications in Sherpa from the Recent Applications menu, because Load opens a file browser on Sherpa’s host, while Apex looks on its host for files. The workaround for loading a new application is to load it using the Apex Listener (see Appendix A); subsequently it will appear in the Recent Applications menu.

• If you attempt to run applications in the Listener, trace output will appear in a somewhat unreadable format. Enter the following to make the trace more legible: (setq *trace-destination* 'listener)

• The extension facility of Apex has not yet been tested.

• The Emacs interface for starting Apex has not yet been tested. (You can start Apex in an Emacs shell and get most of the benefits).

• This distribution does not include FASL files of the Apex system, due to a problem in the Apex load configuration. The FASL files are useful if you want to load Apex into an Allegro Common Lisp development environment.

Upgrading existing applications

You must make the following changes to your existing applications to enable them to work in Apex 3.0.

• The :init-sim argument of defapplication is no longer supported. A new argument :type is used to specify the application’s type. See the defapplication section in Chapter 5 of the Apex Reference Manual.

• The PDL built-in form start-activity (but not the Lisp function) has been obsoleted and must be replaced with definition and calling of primitive procedure. For example, given the following code:

Replace this code with:

In general, the rules for transforming start-activity based code to the new format is as follows (not all are necessarily applicable).

• Replace the activity class named in the call to start-activity with a new primitive procedure.

• Replace the call to start-activity with a call to this new primitive.

• The first argument to start-activity is a resource. Either pass this resource to the primitive (i.e. make it a variable in the primitive’s index) or reference it directly inside the primitive. In either case, add a profile clause in the primitive for this resource.

• If the start-activity call has a :duration argument, add a duration clause to the primitive. The duration value can either be passed into the primitive as a variable in its index, or coded explicitly in the primitive.

• Other arguments passed to start-activity (e.g. :object) can be passed to the primitive as variables in its index.

• Replace the update-activity method of the activity class with an update clause in the primitive.

• Replace the complete-activity method of the activity class with an on-completion clause in the primitive.

• Replace the initialize-activity method of the activity class with an on-start clause in the primitive.

• Remove apex-info forms from files (they will now only generate a warning if left in).

• Replace period clauses with either repeating or responding (period will still work, but now prints a warning that it is deprecated).